Torchwood is called in to investigate a burglary in which the robbers
have been horribly injured under mysterious circumstances. One of their
victims, Beth, turns out to be an alien sleeper agent -- a soldier
planted on Earth with false memories in order to gather information for
an invasion. With no recollection of her past life, Beth is adamant that
she retain her human persona... but the rest of her sleeper cell has
already been activated.